Optical articles including ophthalmic lenses may comprise Hard Multi-Coats (HMCs). Such HMCs can comprise several material layers optionally capped by a top coat film. The top coat film can comprise anti-scratch coatings, anti-reflection coatings, anti-smudge coatings, hydrophobic coatings, and the like to enhance the optical performance of the optical article and also the life of the article. Existing HMCs of optical articles are commonly comprised of materials such as indium tin oxide (ITO), a transparent conducting oxide. ITO can be used in general for electro-optical applications. An ITO conductive layer can provide optically clear transparency and antistatic properties to an article. Aside from ITO, the electrically conductive layer of an optical article may comprise a metal oxide selected from tin or zinc oxide, as well as mixtures thereof or an inorganic oxide containing any one of indium, tin, zinc, and other elements or two or more of the elements. The ITO can be applied as indium tin oxide—a solid solution of indium(III) oxide (In2O3) and tin(IV) oxide (SnO2), for example, 90% In2O3, 10% SnO2 by weight that can be typically transparent and colorless in thin layers and can serve as a metal-like mirror in the infrared region of the electro-magnetic spectrum. Thin films of indium tin oxide are most commonly deposited on surfaces by electron beam evaporation, physical vapor deposition (PVD), and/or a range of sputter deposition techniques. Other techniques, such as, but not limited to, methods other than PVD, may be used to apply the ITO, such as, for example, chemical vapor deposition (CVD), or chemical immersion, for example. However, materials such as ITO can be disadvantageous because they can lack strength and thermal resistance, and thereby may not effectively improve the mechanical performance of a HMC.
There is a need for an alternative HMC that can provide an optically clear coating and that can provide good mechanical strength and thermal properties for optical articles, such as ophthalmic lenses. Presented herein is an optical article that comprises at least one of a substrate, a primer layer, and a HMC that comprises at least one layer. In one aspect, the HMC can comprise a plurality of layers. At least one layer of the HMC, the primer layer, or the substrate, can comprise a material that can provide good mechanical strength and thermal properties. This material can be a carbon allotrope. The carbon allotrope can be a graphene material, graphite, carbon nanotubes, fullerenes, or similar materials, or mixtures thereof. Graphene, in particular, has good mechanical strength and elasticity, as well as good electrical and thermal properties that can be advantageous for use in an optical article, particularly a HMC of an ophthalmic lens.
Carbon nanotubes (CNTs) are another type of carbon allotrope which can be used as a mechanical performance enhancer and for anti-static properties of various coatings. Such material properties of carbon allotropes may be used to provide reinforcement for even better mechanical strength and thermal resistance for improved HMCs compared to existing HMCs. Also presented herein is a method of manufacturing an optical article that comprises at least one carbon allotrope.
Other objects, features and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.